// ========================================================================
// Copyright (c) 2004-2009 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// The Eclipse Public License is available at 
// http://www.eclipse.org/legal/epl-v10.html
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// You may elect to redistribute this code under either of these licenses. 
// ========================================================================

package org.eclipse.jetty.util.ajax;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.eclipse.jetty.util.ajax.JSON.Output;

/* ------------------------------------------------------------ */
/**
 * Convert an Object to JSON using reflection on getters methods.
 */
@SuppressWarnings({ "unchecked", "rawtypes" })
public class JSONObjectConvertor implements JSON.Convertor
{

	private boolean _fromJSON;
	private Set _excluded = null;

	public JSONObjectConvertor()
	{
		_fromJSON = false;
	}

	public JSONObjectConvertor(boolean fromJSON)
	{
		_fromJSON = fromJSON;
	}

	/* ------------------------------------------------------------ */
	/**
	 * @param fromJSON
	 * @param excluded An array of field names to exclude from the conversion
	 */
	public JSONObjectConvertor(boolean fromJSON, String[] excluded)
	{
		_fromJSON = fromJSON;
		if (excluded != null)
			_excluded = new HashSet(Arrays.asList(excluded));
	}

	public Object fromJSON(Map map)
	{
		if (_fromJSON)
			throw new UnsupportedOperationException();
		return map;
	}

	public void toJSON(Object obj, Output out)
	{
		try
		{
			@SuppressWarnings("unused")
			Class c = obj.getClass();

			if (_fromJSON)
				out.addClass(obj.getClass());

			Method[] methods = obj.getClass().getMethods();

			for (int i = 0; i < methods.length; i++)
			{
				Method m = methods[i];
				if (!Modifier.isStatic(m.getModifiers()) &&
					m.getParameterTypes().length == 0 &&
					m.getReturnType() != null &&
					m.getDeclaringClass() != Object.class)
				{
					String name = m.getName();
					if (name.startsWith("is"))
						name = name.substring(2, 3).toLowerCase() + name.substring(3);
					else if (name.startsWith("get"))
						name = name.substring(3, 4).toLowerCase() + name.substring(4);
					else
						continue;

					if (includeField(name, obj, m))
						out.add(name, m.invoke(obj, (Object[])null));
				}
			}
		} catch (Throwable e)
		{
			// e.printStackTrace();
			throw new IllegalArgumentException(e);
		}
	}

	protected boolean includeField(String name, Object o, Method m)
	{
		return _excluded == null || !_excluded.contains(name);
	}

}
